In this episode we will have a quick overview of the nRF52840 Bluetooth SoC and Evaluation board.
The video segment discusses Nordic Semiconductor nRF52840 SoC, which is the top end offering of the nRF52 family of Bluetooth integrated SoC. A demonstration of the evaluation board and sample application is also presented.
Nordic has a strong market share in the embedded low-power Bluetooth connectivity space, in no small part due to their silicon offerings as well as developer support via their InfoCenter documentation andDevZone forum.
The featured evaluation board is a reasonable priced platform to get started investigating Bluetooth connectivity and designing peripheral circuits to integrate with the system for platform prototyping.
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For home and/or office networking, wireless is convenient and as Wi-Fi standards evolved the performance has progressed. Despite technological advancements, wireless networking still lags behind wired gigabit Ethernet in practical use.
Here’s my mobile battle station just a few feet away from the network routerconnected via WiFi.
And the same laptop across the house with the same configuration (unplugged power adapter) but attached to Ethernet.
The link speed of the Ethernet connection is always 1 Gbps. The WiFi link speed fluctuates for whatever reasons and for me the reported link speed changes significantly when active vs. idle.
Even if your internet service speed is less than gigabit, local network access between computers for file/media shares, automated backup, and the like also benefit from 1000 Mbps transfer capacity. Over SSH/SFTP I usually see around 95-100 MB/s transfer rate copying large files between computers.
Got the need for speed? Good. Here’s an easy quick start:
Do the same for another computer and you should be able to move bits between them much faster than over WiFi.
If all your computers are in the same room as your router, or you don’t mind having wires run and taped along the hallway, you’re good here. Read on if you want to possibly put in a clean and tidy installed network run within your home
**Usual disclaimers of your own risk and responsibility apply in regards to working on your own home or with permission from property owner. Only you or your hired contractor can judge the most appropriate work actions for your home configuration.
To run Ethernet throughout your home, you’ll want to start off with a Cat5e Ethernet Cable Kit that for a reasonable price should gets you a bulk supply of Cat5e cable as well as connectors and handy tools.
You have to know your home to figure how to approach your home wiring runs. I can go over what I’ve done in a few scenarios.
When I lived at home when we still had carpet, an easy and minimally intrusive method was to tuck the Ethernet cable underneath the baseboard behind the carpet edge, and terminating the ends with an RJ-45 Jack and installing it within an RJ-45 surface mount box.
A Fish Tape tool can help continue a cable run underneath a carpeted doorway.
In another home, a wood flooring project was the perfect opportunity to run network cabling within the expansion gap between the flooring and the wall.
In our present dwelling with wall to wall tile flooring already installed in half of the house, I ran the wiring through the crawl space.
With a stud finder, I was able to plan out the drop locations and cut out some drywall, drill some holes through the sub flooring and pulled the cables through.
With a pair of known good Ethernet cables you can test the end-to-end connection jacks with your kit cable tester, as well as testing the custom length node cables you’ll make with the leftover bulk cable, crimps, and crimp tool.
To fan out your connections from the wall jack or wall mounted box, run a cable from the wall to a network switch, then attach the computers in the room to the switch.
With a small outlay for hardware and time commitment, you can enjoy years of reliable network connectivity within your home/office for work and leisure.
Addendum: If you do plan to cut holes within your non-new build home, be prepared for any surprises. Like, this gent and some of his buddies were hiding behind the wall I cut open.
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In the era of video conference calls, practically every work desk has become a mini-studio setup equipped with web cameras and headsets interfaced with an array of collaborative platforms. Lighting, despite being just as important to your presence presentation, often tends to be an after-thought as evidenced by silhouetted faces and harsh shadows among your meeting’s gallery view.
Of course, with physical space permitting you could look into some Softbox Lighting Kits to Zoom your way to the Most Photogenic Teams Player. Indeed I have found such lighting kits fun to use and are of great value, but understandably might not be appropriate for a smaller dedicated workspace.
At minimum for overall reduced eye strain is to have a desk lamp to illuminate your general working area, as well as doubling as a light source for your video feed.
I tend to favor the articulating arm kind of lamps as they can be positioned downward to a specific area of interest to aid in minute tasks like PCB assembly or focused reading. OR to borrow from photography practices, can be aimed towards the ceiling to produce a soft bounced light effect. The gentler, well defused lighting avoids that “deer in the headlights” look from having a major light source pointed straight at you.
A more directed video light can be used to fill in the shadows that naturally occur on your face while on camera. This compact, yet versatile Neewer kit has been my battle station’s MVP.
This video light is USB (USB-A) powered and with its minimal power draw should work with practically any computer or mains USB port/charger. The included tripod is height and tilt adjustable.
Best of all, the light output is dimmable via an in-line controller to let you dial in the fill light to match ambient conditions.
Unless you’re going for that streaming gamer vibe, or just going to use a software superimposed background effect, you won’t want to forget about background lighting if your room is dim during your conference. An overhead light can be switched on if needed, or positioning a floor lamp in a corner to help.
Cheers to improving your presented image while reporting out your project progress and status in the morning, and showing off the kids brightly in the evening family call.
About a year ago I had a conversation with a professional friend about our work arrangements at the time, and what we’d do in terms of bench setup if we each were to do full-time independent consulting and contracting. Almost immediately we unanimously agreed on having two (2) computers.
The rationale is pretty obvious: loss of use of computing tools for design and development is a major risk to revenue when you’re the invoicing party. However, being stuck in the water when your only corporate issued rig gives up isn’t fun either.
I was reminded of that think-storm session earlier this week, right in the middle of a rather intense sprint.
Luckily, this halting-on-boot laptop wasn’t the only computer I have for development, because otherwise it would have been very inconvenient in the project support, and a potentially major hassle should major servicing be required during COVID-19 shelter-in-place.
I experienced no loss to productivity because I perform most development with another computer that is my daily driver. On the table next to it is my secondary computer, which while not identically configured, can stand in with the same tool chains should need arise.
Of course, a sound data backup and recovery plan is always necessary and most people (hopefully) have that in mind, especially as some computer models tightly integrate storage modules rendering recovery difficult when the system fails to operate. Redundancy in workstations and other important tools may not often be in the forefront of thought, but is an important consideration. Even if you’re able to pick-up a new computer from the store within the hour, it may take a day or so to load up your software tools to get back to being productive.
It took me a few months to determine the most appropriate redundant systems strategy. At first, I had thought of keeping two mostly identical computers but realized quickly that one of them would most likely collect dust. Two exact setups are also potentially vulnerable to same-time failure if for example, the OS vendor pushes out a faulty automatic update.
I presently settled upon maintaining complementary platforms that are able to either host cross-platform tools natively and/or virtualize operating environments that can be replicated. This way, the computer resources all get utilized on a regular basis and have enough overlap should one fail at an inopportune time.
Q1-2020 has featured audio-video conferences in the spotlight. While the benefits and value of remote collaboration is greatly acknowledged and appreciated, there are some privacy and security concerns that come along for the ride.
What video conference/meeting vendors do with account access and account data once on their platform is really up to their practices. However, for concerns regarding what the vendor client tools might do in regards to residual background processes or adding additional unwanted software packages, you have some mitigation options through containment.
Dedicate a computer for conference meetings.
Vendor clients have no access to local data on your primary workstation due to air-gap.
Yet another computer to own and maintain. Won’t allow you to directly share content you might need on your primary workstation, unless you go through setting up network file sharing which is not without its own concerns.
Dual-Boot: One computer but two disks/partitions. Similar pros/cons as dedicated computer.
Can run in parallel within your workstation in it’s own container. No to (relatively) low hardware cost. Can share content with your host workstation through VM filesharing.
Your Performance May Vary. Definitely will want to do some preflight testing and have a backup ready to go should system fail to perform adequately during a call.
For our discussion, we’ll focus on virtualization. Before we continue…
THE DISCLAIMER:The contents of this article are intended for your personal use on your privately owned computing tools. Please adhere to your company’s policies and usage specifications for software, subscriptions, and computer tools provided to you for company use. DO NOT use this guide to circumvent company IT policy. Don’t blame me if Nick Burns your Company’s Computer Guy becomes angry and sarcastic with you. Other usual at-your-own-risk, no warranty, no liability disclaimers also apply.
Oracle Virtualbox is a free virtualization software that runs on Windows, Mac, and Linux hosts. It allows you to setup a virtual computing environment and allocate CPU, Memory, Video, storage, USB, file, etc resources to expose to the virtual …box.
For “Guests”, that is, the operating system running inside your container, Virtualbox supports several systems. However, Linux is free and easily accessible. I suggest Linux Mint.
A note on versions: The procedure in this article uses a Linux Mint 18.3 XFCE Host, using VirtualBox 5.2, and running a Linux Mint 18.3 XFCE guest. For whatever reason, the GUI presented in VirtualBox 6+ doesn’t play well with my 4k/UHD display, and Mint 19.3 apparently needs a Video Controller option that is only presented in VirtualBox 6+ to work correctly.
Download and install the VirtualBox software, and the associated extensions package. Then download the Linux ISO of your choice.
In VirtualBox, press “New” to create a new system profile.
Give your new system a name, set the type to Linux, and select the closest “Version”, then press Next.
Select “Create a virtual disk now” and press Create
Be sure that VDI is selected, and press Next.
I’ve only ever used “Fixed Size” because I have the Need for Speed
For your ‘physical disk’, give it a name/location, and size it just a little more than the minimum system requirement.
Wait for the virtual disk to be created. If the disk is created on an SSD, it won’t take long.
In the left panel of the VirtualBox utility, right click on your newly created system and select “Settings…”
Select “System” in the left pane, and within the “Motherboard” tab, give your virtual system at least 4 GB (adjust more or less, now or later, depending on the performance you are achieving, or available physical memory).
Within the Processor tab, give it as many ‘processors’ you have in the green range, again: more or less depending on performance. This is an allocation setting, meaning the VM will use up-to the specified value.
Select “Display” in the left pane, and within the “Screen” tab, tune the Video Memory if needed.
Go to the “Storage” pane selection, select the virtual optical device, then expend the menu to choose a disc image.
Navigate to the Linux ISO you downloaded earlier. Then Press OK
Just showing the USB Controller setting here. I think it defaults to USB 2.0 (EHCI). If your webcam is choppy within the VM, try changing this to USB 3.0, if supported on your computer.
Close out the settings dialog. Press Start to launch the VM. It should boot up with a “BIOS”, then boot from your Linux ISO.
Press Enter on the keyboard to go. You may to click in the VM window first. –To free the keyboard/mouse from the VM if it locks inside the VM, press the right CTRL key on your keyboard.
The LInux Live CD image should complete booting monetarily into a GUI system. Let’s test that your webcam works.
Open a terminal window, and type in
sudo apt-get install cheese
then press enter
From the VirtualBox menu bar, go to Devices->Webcams and select your webcam to attach to your VM.
Launch the Cheese from the Applications Menu
Verify that your webcam works. If it’s choppy, shut down the VM and try changing the USB setting from earlier, and try it again.
Close out the Cheese utility.
While we could just go conferencing with the live image load, you’ll have to reinstall application with every instance. Instead, let’s go ahead and install the OS to our virtual disk. Couple click on the Install icon on the desktop inside the VM. The Installer will launch.
Select your language
Check the box to install third-party software.
From here, just go with the defaults and press Next/Continue to install the system. We’re only using this VM for conf calls so this is good enough configuration.
When the installer finishes, it’ll prompt you to reboot. Go ahead. Press enter when it says to remove the boot image, and the VM will restart into the installed system.
Once rebooted into the installed system, pull down the “Devices” menu from the VirtualBox menu bar and select “Insert Guest Additions CD image…”
Double-click on the “Home” icon to open the file browser, select the mounted CD image. Right click in the file area and select “Open in Terminal”
In the terminal, enter
Follow the prompts to install the Guest Additions package. When finished, restart the VM.
With the VM restarted, you should be able to resize the VM by resizing the running Virtualbox window, and/or setting the screen size from the menu.
Its generally a good idea to run system updates right after a new install. Double click on the blue (i) shield in the lower right notification area to bring up the update manager. Follow the prompts to update the utility and system packages.
From here, you can certainly use the installed Firefox browser to access web resources, download and install Chrome if you wish, and access conference via web browser.
For WebEx, the limited testing I did with my account indicates positive potential.
For Zoom (yea, yesIknow…), well I had some stability issues running within the browser within the VM earlier and ended up first resorting to using browser on the Host side (real) computer. Ultimately I ended up running their desktop client so I could see all videos (gallery view) at the same time…then uninstalled it.
I did install the Zoom application within the VM for next Zoom meeting. You can find the download on their website.
Once installed and launched, you get option to join meeting.
Virtualization is quite nifty for containerizing not only for running dodgy conference applications, but its also good for multi-platform testing and computer consolidation. VirtualBox is certainly not the only player in VMs (see VMware and Parallels) and you have your choices in Host and Guest systems.
Online web presence is a requiem for practically every business big and small. Dutifully, that includes establishing a proper web site and appropriate domain name to represent the business.
Oftentimes however, I observe small businesses such as favorite mom & pop dining establishments, or real estate agents, go through the effort of setting up [business_name].com for a web site address, only then to use an email address such as [business_name]@[POPULAR_FREE_EMAIL].com
It certainly works, but definitely could be better. –Potentially worse for professional image if the email goes to an uhm “legacy” internet service provider host. It would be great to setup contact email addresses to use the same domain name. Fortunately, it’s not too hard to accomplish, without having to run your own email server or migrate your existing email accounts.
What you’re going to look for is “Email Forwarding” or “Email Alias.” Once setup, what this will do is the domain will receive any emails addressed to “firstname.lastname@example.org” and forward it to whichever email address destination you’ve set. So even if you use Gmail, Yahoo, Hotmail, or AOL email, you can print your business cards and other promotional materials with an @your_business_name.com email address.
Where to find this setting will depend on your current configuration.
a) If you contracted with a consultant to manage your online presence and have a turnkey service agreement with them, by all means contact and let them know you want an email address at your domain to forward to your usual email address. You can still continue reading below as reference to what your consultant might do.
If you’re managing things partially or fully on your own, then either of these will likely apply:
b) Your domain is setup with a registrar and it points an IP address to a server hosted with another provider – chances are you’re using your registrar’s default DNS server. Somewhere within your host-records configuration there should be an option for Email Forwarding or Alias. If you’re unsure, look through the registrar’s support knowledge base or contact the support team
Other providers should have similar configuration options.
c) If you go into your registrar’s domain setup and you don’t see these DNS options, your domain might be setup to use a non-default nameserver. This may be the case if you’re using the same company for domain and hosting where they have you setup with their “web hosting nameserver”. If the web hosting side presented you a cPanel control panel, you might find the email configuration there.
So far, you can receive emails addressed at your forwarding alias.
No matter what, if you’re writing emails from your Gmail/Yahoo/et.al account, the email headers will show that it is originating from Gmail/Yahoo/et. al.
However, you can set your email account’s “Reply-To” address to your domain forwarding email address. This way, when someone replies to an email, your ‘name@your_business_name.com address will be in the “To:” field. In Gmail, its under Settings->Accounts and Import.
Now, when you go to draft emails, you should get a drop-down option in the “From:” field.
Send some test emails between yourself, maybe get a friend to test it out for you as well to make sure all works as expected. Now you can have consistency with your web address and email address.
If you’re reading this in March of 2020, you might be working remotely if your type of work permits such work arrangement. Generally the “work from home” conjurers up the image of sitting in bed, on the living room sofa, or at the kitchen counter. For those who work from home on an incidental basis (say, just to care for family illness), opening up the laptop and punching away at the dining table between clearing the dishes is passable for the limited time.
For remote work on a regular basis, it is in your and your productivity’s interest to setup a dedicated workspace.
While nice, a spare bedroom turned into a home office is not necessary. And even so, it’s not the bulletproof distraction-free environment as Professor Robert Kelly can confirm. Just a place that you can set aside for ‘exclusive work use’ is sufficient if it can contain the tools and instruments you need for being online, and that space can be left alone when not working.
Generally a proper desk or an available table positioned at a slightly less trafficked part of the residence will do. (The mahogany table in the dining room that’s only used on Thanksgiving and Christmas would qualify). Adding a low bookshelf can add a virtual wall to enclose an otherwise open space if necessary.
The two immediate benefits of a dedicated workspace is
It presents an opportunity for physical separation when working/not-working.
The bench setup is not shuffled around due to other normal home events such as meal times.
The physical separation is important as its really easy to be distracted from work, or not fully unplugging after quitting time. In addition, you being in the dedicated workspace signals others in the home that “you’re at work”.
Often is the case that work projects don’t finish at end-of-business-day and continue the next work day. While you’ll prudently power-off instruments and stow away potentially hazardous items while off of work, the dedicated workspace saves you from daily full setup and tear-down so you don’t have to start every morning unpacking the office station.
If you’d like some ideas: here’s my current battle station, which happens to be in a corner of an otherwise unused guest bedroom:
–As you can guess from the nature of this site, my work involves (small) electronics, firmware, and software.
If you’re tight on space, or just need more room, you might consider a closet office such as my other setup when I used to run two stations.
Adoption and office-culture acceptance of remote work has historically varied but trended upwards in past years. Recent global events have pushed the remote work arrangement to the forefront, and variousresearch has indicated mutual benefits for companies and staff.
As working remotely is now in the spotlight, lets join together show the world that as the sh!t. hits the fan, we can still get sh!t done!
For more tips on successfully working from home, check out:
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During a recent visit to Costco, the kids and I walked past the KAWAI pianos on roadshow display. We were admiring one of the models that was fully acoustic on the instrument side, but had some embedded electronics and firmware that automated music playing by mechanically actuating the keys.
The nice sales gentleman made his pitch that it’s value in entertaining without requiring an actual piano player. The model on display was $18,999. Considering that I look like a broke college kid most days and our cart contained other low-cost items, I’m hoping the sales gent was being somewhat joking in a deadpan manner and not expecting us to actually place an order on the spot. Plus, I had earlier remarked to my daughter that the price of the piano was just as much as my daily driver sedan.
But it got me to recall that our more modest digital piano is equipped with a USB (USB to Host) port. I was able to confirm after quick documentation review that the USB port presents itself as a MIDI device. I found a USB A/B cable and attached it to the nearby Linux laptop. The OS detected it just fine without requiring any additional drivers or manual kernel module loading.
To anyone at Yamaha reading this, THANK YOU for building devices with standard interfaces without requiring proprietary software or connectivity hardware. For that, you rock.
I spent the next few days downloading MIDI files of various popular music arranged by random folks, and piped them to the piano for play-by-instrument using Rosegarden, which is a music composing and editing program. How well a song performs depends on the arrangement, and the nature of the song’s genre contributes as well. (popular 90s era Latin Pop/Dance sound amazing)
For those unfamiliar: compared to a sound file (.wav) that contains a pulse-code sequence to represent a audio signal, a MIDI file is essentially a sequence of instructions to command an instrument device (physical, or software emulation) to play notes/sounds with prescribed voice and other parameters as well as set instrument controls.
But in my quest for semi-unattended playback, I wanted something that I could just load a playlist and go. I didn’t find such a program, so I went ahead and drafted up a Python script.
The relatively basic script scans the directory for MIDI files into an array, randomly sorts the array, and then calls ‘aplaymidi’ program that comes with Linux with the MIDI port number and file name to play. It features some filename character escaping and very little robust error case handling. But it does catch CTRL+C to gracefully (as best it can) quit out of the loop.
The script runs on the laptop as expected. But because it’s Linux + Python, it also runs on a Raspberry Pi.
I had a moment of pause wondering if the plug-and-play would indeed work on the Pi since it’s ARM based vs. x86/x64, but it was for not because it detected just fine.
Here’s the script running on the Pi, invoked from an SSH terminal shell, since I’m running the pi headless (no monitor or keyboard/mouse attached)
It is truly amazing that I can attach a $35 computer and “upgrade” a lower cost instrument with feature(s) found on models costing hundreds or thousands more!
With the GPIO pins on the RPi, I could certainly attach some hardware buttons and handle events for Play/Stop, FF, and Prev. –For another time, or I’ll leave it as an exercise for you the reader.
Addendum: As with most software projects, the same objective could have been accomplished with other solutions (in this case: shell script, perl, etc) but 1) I wanted to expand my python-fu, and 2) Python is the cool language/tool of this writing. Not that I’d universally suggest everyone to chase every fad and trend, it does help to keep up with available options and general marketshare. If given the chance to work on a lower risk project, I do encourage you to try out and evaluate new or new-to-you tools to solve the problem rather than always using your go-to choices.
I’ve been working on a Bluetooth Low Energy (BLE) based project for the past year, using the Nordic nRF52 integrated SoC. Its powered by a 64MHz ARM Cortex M4 core and Nordic provides good software stack and SDK support.
In keeping up with current industry developments, I was excited to hear about a month ago that STMicroelectronics announced their BLE SoC kit: the STM32WB.
I’ve also worked with ST microcontrollers for the past several years, and they also provide good chip level driver library support. The eye-catcher on their BLE chip is that it’s a dual-core design: A 64MHz ARM Cortex M4 to run the application, paired with a 32MHz Cortex M0+ core to run the wireless stack.
After a few weeks of scoping limited inventory, I was able to score an Eval kit:
One of the nice options in working with ARM microcontrollers is that we’re spoiled for choice on IDE options. The Free option is the one I featured today: GNU MCU Eclipse. It is a bit of a setup/install process, but the guide is pretty straightforward and it gets you a $0 development environment that is not feature or code-size limited.
In the toy chest realm, there are many job roles and responsibilities that are assigned to different toys, or kinds of toys. The levels of “skills” and “how equipped” each toy has to perform its duties varies. All not too dissimilar to career professionals.
Take LEGO building blocks for example. They are tasked to encourage imagination, problem solving, and physical dexterity. The molded plastic structures are well designed for reliable and repeatable inter-connectivity. By nature of mechanical design, LEGO blocks are well suited for harsh environments that subject heat (hot car), water (bath tubs, sinks), and physical stress (don’t try stepping on one!).
Many other kinds of toys follow the same job roles and in-built traits that help fulfull those responsibilities: die cast cars, Lincoln Logs, Mr. Potato Head, etc.
Then we come to the stuffed toys, or plushies. Honestly the world of plushies could be discussed as one of their own, but for now let’s just simplify the genre as a general group.
When a kid is given (or finds) a plushie, a job assigned to that plushie is to encourage imagination. But it’s also assigned a role of emotional and morale support. Or maybe its assigned a static decorative item to spend most of its days safe on a shelf. A lot of it comes down to the client (the child).
That plushie might have to “work” long hours and be on-call at nights. Or defend as night watch and doze during the day. It may be carried along everywhere and possibly left anywhere.
The design and equipping of plushies somewhat contractracts itself. Most are fabricated with soft materials to appeal to senses, but the porous, absorbent fabrics don’t stand a chance against unwanted interactions with liquid substances. Soft feely materials don’t hold up well against rigorous cleaning cycles, so wear and tear is very present and observable.
Despite those head winds, plushes fulfill their duties very well. They are loved well by their owners. And they become “well loved”. Like “Pur-See” in my own home:
Which brings up one other important design and equipping detail on plushes: they are very prone to damage. A loved but soiled plush requires a gentle cleaning approach because while a plush can be physically replaced, its “not the same”.
What can we learn from plushes:
Core competencies do not fully detail someone’s ability to deliver.
A person’s capability to fulfill responsibilities are not limited to the equipping and skill-set present when they start the job.
Unexpected challenges on project objectives are best met with systematic strategies and due diligence to arrive to most appropriate corrective actions provided the circumstances and risk assessment/mitigation.
While you can always look for another (developer, engineer, analyst, assistant, <job role> ) to fill a vacant position, you know it won’t be the same as working with Jeff, Jennifer, or Justin.
On the flip side, you can build in redundancy by cross-training your team members, keeping contact with dependable people in your network, and being ready to bring in additional help. After recently surviving an uhm… incident, “Pur-see” will soon have a twin sister and cousin.